In recent years, in a luminaire, an incandescent lamp and a fluorescent lamp used as an illumination light source are replaced with a light source that consumes less energy and has longer life such as a light-emitting diode (LED). For example, new illumination light sources such as an electro-luminescence (EL) and an organic light-emitting diode (OLED) are also developed.
A two-wire dimmer is configured to control a phase in which a triac is turned on. The two-wire dimmer is spread as a dimmer for the incandescent lamp. Therefore, it is desirable that the illumination light sources such as the LED can be dimmed by the dimmer.
It is an object of the present invention to provide a power supply for lighting and a luminaire that can continuously change an output current using a dimmer that performs phase control.